Products that are presently available to whiten teeth include a variety of different ingredients, and the primary active ingredient is often a peroxide source such as hydrogen peroxide. The use of peroxide agents can present difficulties in both formulation and long term stability of the resulting compositions. Thus, alternative oxidizing agents with improved stability are desired.
Peroxysulfuric acid, and its salts, the peroxysulfates, are powerful oxidizing and stain removing agents. They are currently used for a variety of industrial and consumer purposes, including denture cleaning. The most common peroxymonosulfate oxidizing agent is potassium peroxymonosulfate, commonly referred to as MPS.
Potassium monoperoxysulfate has seen limited use in dental whitening compositions because of its instability in aqueous solution, especially in aqueous solution near or above neutral pH. In fact, potassium monoperoxysulfate has been known to degrade even in the presence of small quantities of water and heat. Thus, there is a need to provide a stabilized oral care product containing an effective amount of potassium monoperoxysulfate. It is desirable to provide improved oral care formulations which combine the relative stability of monoperoxysulfate salts in an anhydrous environment, with effective whitening and dispensing characteristics.